Bundle Identification problems

I am in the process of publishing my first app to the app store and have encountered several problem trying to figure out what the bundle ID is/should be for my app. I don't have a domain and I don't have a company so its unclear to me as to what I should be reading or typing concerning my "bundle ID".

By default it is com.companyname.$(PRODUCT_NAME:rfc1034identifier}. So if I don't have a company or a domain what should it be?

And for an easier question: if my target platform is the iPhone/iTouch does my program still have to work with the iPad (I don't have an iPad to test with).